Apparently, the U.S. Naval Research Laboratory (NRL) is working on developing underwater photovoltaic solar technology. Maybe it’s just that I grew up on the beach in Southwest Florida and am a Pisces (fish), but I think this is completely wicked awesome. Here’s the full announcement from NRL:

Scientists at the U.S. Naval Research Laboratory, Electronics Science and Technology Division, dive into underwater photovoltaic research to develop high bandgap solar cells capable of producing sufficient power to operate electronic sensor systems at depths of 9 meters.

Power density of GaInP and crystalline silicon cells, underwater, as a function of depth. (U.S. Naval Research Laboratory)

Underwater autonomous systems and sensor platforms are severely limited by the lack of long endurance power sources. To date, these systems must rely on on-shore power, batteries or solar power supplied by an above water platform. Attempts to use photovoltaics have had limited success, primarily due to the lack of penetrating sunlight and the use of solar cells optimized more towards the unimpeded terrestrial solar spectrum.

“The use of autonomous systems to provide situational awareness and long-term environment monitoring underwater is increasing,” said Phillip Jenkins, head, NRL Imagers and Detectors Section. “Although water absorbs sunlight, the technical challenge is to develop a solar cell that can efficiently convert these underwater photons to electricity.”

Even though the absolute intensity of solar radiation is lower underwater, the spectral content is narrow and thus lends itself to high conversion efficiency if the solar cell is well matched to the wavelength range. Previous attempts to operate solar cells underwater have focused on crystalline silicon solar cells and more recently, amorphous silicon cells.

High-quality gallium indium phosphide (GaInP) cells are well suited for underwater operation. GaInP cells have high quantum efficiency in wavelengths between 400 and 700 nanometers (visible light) and intrinsically low dark current, which is critical for high efficiency in lowlight conditions.

The filtered spectrum of the sun underwater is biased toward the blue/green portion of the spectrum and thus higher bandgap cells such as GaInP perform much better than conventional silicon cells, states Jenkins.

Preliminary results at a maximum depth of 9.1 meters reveal output to be 7 watts per square meter of solar cells, sufficient to demonstrate there is useful solar power to be harvested at depths commonly found in nearshore littoral zones.

Oakland, 7 June 2012 — Campaigning organizations from around the world will join forces on June 18 for a 24-hour 'Twitter storm' in which tens of thousands of messages will be posted on the social networking site demanding that world leaders use Rio+20 to agree to end fossil fuel subsidies.

The 24 hour clock will start at 6PM UTC in Sydney, when activists will begin to flock to Twitter with messages that will also be projected in iconic spots in Sydney, New Delhi, London, Rio, and other locations. In recent weeks campaigning groups have collected over 1 million signatures demanding that leaders act now to end subsidies and start to invest in clean energy solutions. (1)

According to figures compiled by Oil Change International, countries together are spending as much as $1 trillion dollars annually on fossil fuel subsidies. (2) The International Energy Agency estimates that by cutting these subsidies, the world can cut global warming causing emissions in half and significantly contribute to preventing a 2 degree temperature rise, the number most scientists say we need to stay under to prevent runaway climate change. (3)

"We are giving twelve times as much in subsidies to fossil fuels as we are providing to clean energy, like wind and solar. World leaders shouldn't be subsidizing the destruction of our planet, especially since these subsidies are cooking our planet," said Jake Schmidt, International Climate Policy Director at the Natural Resources Defense Council.

In May, leaders of the G20 again pledged to eliminate fossil fuel subsidies. They first made the commitment in 2009 but have yet to implement the policy change at the country level.

While global warming emissions rise and gas prices spike, fossil fuel companies continue to make massive profits, which brings into doubt the need for subsidies. ExxonMobil, for example, paid an effective US federal tax rate in 2010 of 17.2 percent, while the average American paid 28 percent.

Can you build an app in a weekend? Do you thrive in dynamic teams? Are you a creator, visionary and executor all in one? This weekend's hackathon in Oakland promises to provided another platform for all those hackers looking to intersect the emerging field of clean energy, tech and the internet,…

Richard Matthews of Global Warming is Real has put together a great post on 40 eco-apps for smartphones. He used a variety of sources and the list looks like it could be very useful to anyone with a smartphone. Here’s the post:

Technology may not be a panacea to solve the climate crisis, but green applications (eco-apps) are helping to drive awareness and foster responsible action. There was a time when eco-apps did little more than provide lists of so-called "green" products and services. Now green-themed apps have turned…

To some of you, there may be nothing new here for you, but I hope and think this will be an interesting, informational post for most. Via sister site sustainablog, here’s a good post on what a heat pump is:

Heat pumps provide efficient, reliable methods of heating homes and buildings. Because they use much lower amounts of fossil fuels, they also help reduce carbon dioxide emissions and other greenhouse gas emissions. A heat pump draws heat from the ground, or from outdoor air, and transports it to another…

Working in his lab at the NREL Outdoor Test Facility, NREL scientist Michael Kempe measures the "creep" of the top and bottom glass of a solar module, testing the encapsulant and demonstrating how enough stress can produce a spectacular failure. Credit: Dennis Schroeder

During 30 years on a rooftop, a solar panel gets bombarded by UV rays, soaked by rain, buffeted by wind, pounded by hail.

How well it stands up to that beating is a crucial factor in setting the warranties of solar modules — and in convincing the public that solar energy can be counted on like the sun rising in the east.

The U.S. Department of Energy’s (DOE) National Renewable Energy Laboratory (NREL) plays a crucial role in improving the reliability of the photovoltaic (PV) panels that are being installed on rooftops in record numbers.

NREL helps set standards for reliability and serves as a neutral third party in tests of manufacturers’ new solders, edge seals, and glues. At its Golden, Colorado, campus, NREL subjects solar panels to heat, humidity, and mechanical stress to simulate conditions in Denver, Phoenix, the Philippines, and elsewhere.

In March, leading scientists and engineers in the industry gathered at NREL for the PV Module Reliability Workshop. The workshop encouraged a frank discussion of reliability problems that can plague solar power companies.

What standards are needed for the glue in the edges that seal a panel’s top and bottom? How does weather affect cracking? What can be done to prevent one glass panel from creeping away from the other?

NREL scientist Michael Kempe holds PV samples he is exposing to a saturated salt solution to control humidity. The samples are being tested for possible failures. Credit: Dennis Schroeder

NREL Stresses Edge Seals to Predict Failure

Solar modules must be sealed to keep out moisture — and that’s why edge seals are so crucial.

On what looks like a whirling see-through geodesic dome — albeit just two feet in diameter — NREL scientists attach matchbook-sized samples that simulate the construction of PV modules to determine at what combination of UV radiation, high temperature, high humidity, and mechanical stress those samples can fail.

It’s important that manufacturers not just check for single stresses. By demonstrating that a combination of two or three factors can cause a failure, NREL is helping manufacturers prepare for the worst.

“We help manufacturers to know what kind of stress to put on their samples to determine if Sample A is better than Sample B,” Kempe said. “Every tiny detail, every aspect of these things has to be examined.”

A typical 12-millimeter-wide edge seal should keep out moisture anywhere in the world — from Salt Lake City to Bangkok — if it maintains a good adhesion, Kempe said. And the cost is between $1 and $2 a module, whether it is a tape-style edge seal or a hot-melt extrusion.

In the case of “creep,” NREL’s sophisticated tests showed that the problem isn’t as big as was feared.

In a solar module, two pieces of glass are adhered together with a plastic encapsulant that may be solid at one temperature but flow — or “creep” — at another temperature. If it flows during the expected lifetime of a solar module, solar panel components can be displaced, and that can cause a short, break electrical connections, or even cause fires.

The stakes are high: a one-centimeter creep can expose live wires to the elements, and that can cause arcing or other serious safety problems.

NREL’s tests found that most encapsulants used today or proposed for future use do a very good job of preventing creep. But showing that failure is possible keeps manufacturers from becoming complacent.

Last summer, Kempe and his colleagues used eight different encapsulants from six manufacturers to assemble several mock and actual solar modules. The scientists then evaluated them side by side in an objective manner, and in a way that uncovered strengths and weaknesses of the various encapsulants without pointing fingers at individual companies. The industry’s trust in NREL made the tests possible. “They were able to participate without the fear of being singled out,” Kempe said.

The researchers put insulating materials on the test modules and deployed them in Arizona so they would reach the highest temperatures (104°C) that are likely in the field.

The only material that crept significantly in the outdoor experiments was one that was intentionally formulated improperly so that it would still melt at moderate temperatures.

“All the other plastic materials that people in the industry were considering for encapsulation were essentially OK outdoors,” Kempe said. “It would only be under very extreme circumstances that you might have a problem. The standards community realized that this stumbling block was not nearly as big an issue as was suspected.”

Stress, Temperature Tests Help Prevent Cell Overheating

Shown here is a close-up of the inside of an Atlas CI 4000 Xenon Weather-Ometer used to test small samples of solar panels. NREL scientists apply temperature, humidity, and mechanical stress to the samples to show industry how they can fail. Credit: Dennis Schroeder

Shown here is a close-up of the inside of an Atlas CI 4000 Xenon Weather-Ometer used to test small samples of solar panels. NREL scientists apply temperature, humidity, and mechanical stress to the samples to show industry how they can fail.

NREL also works on the problem of concentrating PV cells overheating in a module. Concentrating PV uses lenses to focus more sunlight on a solar cell. The solder or epoxy that adheres the panel’s glass and edges will fatigue with time because of temperature changes that happen with the weather, NREL scientist Nick Bosco said. When the attachment goes bad, heat can’t escape, and the cell overheats.

NREL uses high-frequency weather data to model the changes in cell temperature for Houston, Los Angeles, Albuquerque … wherever a company wants a climate test. The data are publicly available.

The most damaging locales are those with high temperatures and partly cloudy skies. The frequent temperature changes when clouds pass by can cause extra stress. “In Golden, Colorado [site of NREL's main campus], where we get hot mornings and then clouds roll in every afternoon, that can be more damaging than in Phoenix where you don’t have many clouds,” Bosco said. “We’re early in the process, but we’re seeing easily a 20% to 40% difference between certain locations.”

To test the effect of temperature cycles on the modules, NREL uses various solders and epoxies to attach pieces of the panels, and then exposes them to different temperatures at varying intervals. Researchers test thermal cycling in indoor chambers and expose modules to outside conditions, comparing the results.

“We’re interested in how cracks grow in the solder as the module goes through cycles,” Bosco said. “Our instruments can image the cracks on a computer, analyze them, and measure their size. We’ll do that periodically, then put the module back in the chamber, do more cycles, then measure the growth rate of the cracks as a function of the number of cycles.”

Bosco is working on models and experiments to determine the amount of damage the attachment will accumulate. The goal is for the indoor test chamber to accurately reflect outdoor conditions.

“The amount of damage the attachment accumulates is different for every city, and we’re hoping to model that,” Bosco said. “We’re hoping to be able to make real-life predictions based on location.” So many cycles in the chamber is equal to so many years outside. “So, a company might expect similar crack growth after so many years.”

The challenge for industry is to design solar modules that are very durable and reliable, yet not overly expensive. NREL scientists and their industry counterparts agree they can meet that challenge.

“They’re looking for a route to a less expensive design and architecture of a cell assembly,” Bosco said. NREL is able to figure out why a solution works, not just that it does work. It can report that a change in design or materials has this or that consequence in reliability. And NREL shares that knowledge with the industry to help the technology move forward.

NREL scientists and their industry partners have learned that an accelerated test will mean different things in different locations — and that the material and architecture of the design can influence reliability dramatically. “You can certainly have an expensive bad design,” Bosco said. And, of course, a good product that is incorrectly installed can fail.

As tempting as it is to accelerate the testing so that new, presumably better products can get to market sooner, testing experts know that validating a product for 20 or 30 years of useful life is complicated without comparisons to real-life durability.

So, NREL and the industry keep a poultry analogy in mind. “When you’re trying to hatch an egg, you give it 25 days at about 40°C, and you get a chicken,” Kempe said. “If you try to accelerate the time by accelerating the temperature, you get a boiled egg.”

The results of NREL’s testing will provide the technical basis for changes to reliability standards.

Today, the standards aren’t robust enough to predict the overall longevity of solar panels. NREL, the PV industry, and the attendees of the PV Reliability Workshop are working toward the day when tests and standards can determine the lifetime reliability of a module.

“What can come out of this is a graded test sequence,” Bosco said. “If you pass, say, Level A, it means the module is good for a lifetime in these certain locations. A stricter Level B certification will provide a similar lifetime warranty in more damaging locations.”

Westinghouse Solar apparently sees a bright future in Australia. In the midst of merging with CBD Energy, one of Australia’s largest non-utility suppliers of solar energy equipment, Westinghouse and CBD on June 5 announced they are to begin distributing Westinghouse’s DIY “plug n’ play” solar power systems, dubbed Instant Connect, in Australia.

“In parallel with our efforts to complete our pending merger with CBD, both companies are committed to growing the business in a collaborative effort. As a first step, CBD, through its solar subsidiaries, has agreed to market and install our solar power systems in the Australian and other international markets,” Westinghouse Solar CEO Margaret Randazzo stated in a press release. “The Australian market enjoys a sound regulatory environment for solar, and provides an opportunity for us to grow revenue in a non-US market devoid of risk of punitive tariffs.”

For its part, CBD sees promise in Westinghouse’s award-winning plug n’ play DIY solar PV systems, and in the brand recognition of the Westinghouse name. “A key reason for pursuing this merger was the strength of the award winning technology that Westinghouse Solar possesses,” explained CDB managing director and CEO Gerry McGowan. “When coupled with the significant brand awareness the Westinghouse name provides, one of the first items on our agenda was to bring these integrated ‘plug-and-play’ solar power systems, with fewer parts, superior safety and faster install times to the Australian market.”

Australians installing more rooftop solar than grid operators can handle

“After demonstrating the technology to our customers, they have shown strong interest and we are working to make this innovative technology available to them as soon as possible. Other key features such as the web-based system monitoring and better energy collection will be important advantages in the Australian market, which installed in excess of 830 megawatts of solar last year.”

Shipping its Instant Connect solar panels to CDB in Australia may well be a forerunner of assembling them there. In a joint venture with Tianwei, one of China’s largest renewable energy companies, CBD, through eco-Kinetics, is establishing a solar panel and equipment manufacturing operation on Queensland’s Gold Coast.

Australians have taken to installing rooftop solar PV systems so enthusiastically that electricity grid operators have been capping the amount of grid-connected residential solar PV systems.

The issue highlights the ambivalence of large-scale, centralized electric utilities have for distributed rooftop solar power, and the importance of buildiing out smart grid and transmission infrastructure if utilities are to really capitalize on solar and wind energy potential and market opportunities.

Australians’ average energy bills have been rising fast while the cost of solar PV systems has fallen dramatically. The cost of installing a solar PV system in New South Wales (NSW) ranged from A$2,000 ($1,970) to A$12,000 ($11,811), depending on size of system as of October 2011, according to CBD. That results in a payback period of six years at projected electricity prices.

Average energy bills in NSW are now costing between 20 and 30 cents a kilowatt hour, reaching 43 cents at peak. Solar energy, in sharp contrast, costs 5 cents.

CBD-Westinghouse Solar Merger

Westinghouse Solar and CBD Energy signed a definitive merger agreement on May 9. Expected to close in Q3, the agreement calls for Westinghouse Solar shareholders to receive approximately 3.7 CBD common shares for each share held. Preferred shareholders are to receive CBD preferred shares convertible into common stock. Taken together, Westinghouse Solar common and preferred shareholders will own approximately 15% of the merged company, shares of which are to trade on a US stock exchange.

The merger with CBD puts Westinghouse Solar on firmer financial ground while also providing a base to expand internationally. That’s not to say that Westinghouse Solar expects to bow out of the US market by any stretch, however.

On the contrary, management of both companies say they intend to expand in the US. “The merger with Westinghouse Solar is expected to be highly beneficial for CBD. The US market is rapidly developing into one of the largest and most stable end-markets for solar energy systems,” McGowan explained. “The merger provides CBD an immediate point of access with an experienced management team capable of driving rapid expansion for the combined business.”

“We expect to leverage the Westinghouse Solar relationships to provide new opportunities for distributing energy-efficiency products and services produced by our Industrial Energy Efficiency Division and to create new outlets and applications for our proprietary energy storage technology. The merger is an important step in CBD’s strategy of growing a portfolio of revenue streams diversified across profitable customer segments, geographies, and technologies.”

CBD’s also been expanding in Europe. It has secured a $25 million credit facility that enables it to prioritize and develop and expand its project pipeline of European turnkey solar PV projects on a Build-Operate-Transfer (BOT) model primarily aimed at institutional investors. Management estimates the credit facility will “support the development and sale of solar projects totaling more than A$35 million ($34.45 million) revenue per quarter.”

CBD’s total revenue has grown substantially in recent years, from some A$17 million ($16.7 million) as of June 30, 2009 to A$165 million ($162.4 million) at the end of fiscal year 2011. Cash flow, as measured by EBITDA (earnings before interest, taxes, depreciation and amortization) have improved from a negative A$3.3 million to a positive A$7.9 million over the three-year period.

One of the ways the US federal government subsidizes the fossil fuel industry — natural gas and oil distributors in particular — is through Master Limited Partnerships (MLPs). These special purpose investment vehicles exempt investors who form them from certain corporate income taxes. The catch is that MLPs have to distribute most of their income to partnership shareholders on a quarterly basis.

Sen. Christopher Coons (D-Delaware) believes renewable energy industry participants could benefit greatly if they were allowed to form MLPs, and he, along with Sen. Jerry Moran (R-Kansas), on June 7 introduced legislation — The Master Limited Partnerships Parity Act — to make it happen.

"Master limited partnerships have been largely responsible for the tremendous growth in our country's energy infrastructure," Senator Moran said. "In order to grow our economy and increase our energy security, sound economic tools like the MLP should be expanded to include additional domestic energy sources. This legislation simply builds on a successful model, and I look forward to working with my Senate colleagues on policies that will drive innovation, create American jobs, and grow our economy."

Leveling the Playing Field for US Clean Energy Development

As it is, the U.S. tax code confers preferential treatment on investors in oil, natural gas, coal extraction and pipeline projects — they’re the only ones allowed to form MLPs. In fact, natural gas and oil companies are have been benefiting from being able to form MLPs for nearly 30 years.

Odd as its seems, the IRS code specifically excludes MLPs from investing in renewable energy companies and project portfolios, 24/7 Wall St. points out. Coons’ wants to level the playing field. In addition to gaining support from the Obama Administration, his bill has garnered five Republican co-sponsors for his legislation.

“At a time when the United States needs to increase domestic energy production and leaders of both political parties say they support an ‘all of the above’ energy strategy, Congress should level the playing field and give all sources of domestic energy — renewable and non-renewable alike — a fair shot at success in the marketplace,” Coons states.

Fast-track passage of the Master Limited Partnerships Parity Act (MLPPA) couldn’t come at a more opportune time. Key federal renewable energy tax credits are on the wane and federal government stimulus spending enacted to avoid a banking system and economic collapse have run their course. Meanwhile, persistent concerns about a debt-credit crisis spreading from Europe and efforts to rein in bank leverage and boost capital requirements are tightening credit and lending conditions.

Opening Up as Much as $6 Billion of Private Capital for Renewable Energy

Graphic courtesy Sen. Christopher Coons -- MLPPA

Affording renewable energy industry participants, the ability to form MLPs would open up significant new opportunities for them to raise lower-cost capital at a time when financing options are regressing to the point where renewable energy financing is increasingly reliant on tapping the relatively small market for tax equity financing.

As much as $6 billion in capital that’s currently excluded from renewable energy projects might be invested in renewable energy MLPs, according to a study from the Maguire Energy Institute at Southern Methodist University, Paul Ausick noted on 24/7 Wall Street.

As Coons notes, projects put into an MLP portfolio “get access to capital at a lower cost and are more liquid than traditional financing approaches to energy projects, making them highly effective at attracting private investment. Investors in renewable energy projects, however, have been explicitly prevented from forming MLPs, starving a growing portion of America’s domestic energy sector of the capital it needs to build and grow.”

In a June 2 New York Times article, Stanford University’s Dan Reicher and Felix Mormann succinctly explained the boost allowing renewable energy companies to form MLPs would provide to the US renewable energy industry.

“If renewable energy is going to become fully competitive and a significant source of energy in the United States, then further technological innovation must be accompanied by financial innovation so that clean energy sources gain access to the same low-cost capital that traditional energy sources like coal and natural gas enjoy.”

“Master limited partnerships carry the fund-raising advantages of a corporation: ownership interests are publicly traded and offer investors the liquidity, limited liability and dividends of classic corporations. Their market capitalization exceeds $350 billion. With average dividends of just 6 percent, these investment vehicles could substantially reduce the cost of financing renewables.”

Coons’ MLPPA would expand the definition of “qualified” MLP sources to include clean energy resources and infrastructure projects. If passed, MLPPA would allow MLPs to be formed for solar, wind, marine and hydrokinetic, hydropower, combined heat and power, municipal solid waste, geothermal, fuel cells, and closed and open-loop biomass. It would also enable MLPs to be formed for a range of alternative transportation fuels, including cellulosic ethanol, biodiesel, and algae fuels.

A diverse group of clean energy industry leaders, industry associations, and public interest groups are coming out in support of Coons’ MLPPA, including the American Council on Renewable Energy (ACORE), the American Wind Energy Association (AWEA), Clean Energy, Third Way, Covanta, DuPont, NRG Energy, the Solar Energy Industry Association (SEIA), the Wind Development Coalition, the Advanced Biofuels Association, the Biomass Power Association, the Advanced Ethanol Council, Environmental Entrepreneurs, and the Natural Resources Defense Council (NRDC).

Based on the fuel efficiency info just released for the Honda Fit EV, the new leader in the EPA’s fuel efficiency ratings, one of our readers did some quick calculations and came up with some interesting facts. I thought I’d quickly repost a few or these for more eyes to see, and also elaborate on them.

From Bob_Wallace: “kWh per mile for the Honda = 0.29. At $0.08/kWh that’s just slightly over 2 cents per mile.”

He then noted that a 50mpg gas-powered vehicle (aka ‘gasmobile’) would need $1.16/gallon of fuel to drive for so cheaply. I don’t think you can find that anywhere these days, do you?

Notably, not every place has electricity selling for $0.08/kWh. The average price of electricity for residential customers in the US is a little under $0.12/kWh these days (or about $0.0959 for all sectors combined).

But, even if you’re paying $0.12/kWh for electricity, you’d need gas to be at $1.74/gallon for a super fuel-efficient (by US standards) gas-powered car getting 50 mpg to be running for the same price.

However, the average fuel economy of vehicles sold in the US is actually far less than 50 mpg, it’s just approaching 24 mpg (May 2012). For such a car, you’d need gas to be selling for $0.8352/gallon to match the average fuel costs of a Honda Fit EV. Wow, good luck with that!

I’ve got a ton more cleantech stories for you from around the cleantech interwebs this week. I’m going to try a simpler and quicker approach this time by just placing the titles and links alone without any excerpt or summary. Let me know how you like this? Like it more than with the summaries? Prefer having the summaries? Don’t really care?